This Madad was asked by Musa alayhis salam from his countryman with the word istaghaatha “he asked for help” (28:15) and by Dhul-Qarnayan using the term "help me" in Surat al-Kahf (a`eenuni) (18:95) which is the same root as "we turn for help" (nasta`een) in the Fatiha.
Following are proofs from the Sunna for calling out to an invisible helper in a situation of need:
1. Al-Bukhari narrates in his Sahih that our mother Hajar, when she was running in search of water between Safa and Marwa, heard a voice and called out: "O you whose voice you have made me hear! If there is a ghawth (help/helper) with you (then help me)!" and an angel appeared at the spot of the spring of Zamzam.
2. Abu Ya`la, Ibn al-Sunni, and al-Tabarani in al-Mu`jam al-Kabir narrated that the Beloved Prophet Sallallahu alayhi wasallam said: "If one of you loses something or seeks help or a helper (ghawth), and he is in a land where there is no one to befriend, let him say: "O servants of Allah, help me! (ya `ibad Allah, aghithuni), for verily Allah has servants whom one does not see."
Another wording:
3. Al-Bayhaqi narrates on the authority of Ibn `Abbas in "Kitab al-Aadaab" (p. 436) and with a second chain mawquf from Ibn `Abbas in "Shu`ab al-Iman" (1:445-446=1:183 #167; 6:128 #7697) and a third from Ibn Mas`ud in "Hayat al-Anbiya' ba`da Wafatihim" p. 44: "Allah has angels on the earth - other than the [two] record-keepers - who keep a record [even] of the leaves that fall on the ground. Therefore, if one of you is crippled in a deserted land where no-one is in sight, let him cry out: a'înû 'ibâd Allâh rahimakum Allâh, 'Help, O servants of Allah, may Allah have mercy on you!' Verily he shall be helped, if God wills."
4. Ibn Abi Shayba relates in his "Musannaf" (7:103) from Aban ibn Salih that the Prophet Sallallahu alayhi wasallam said: "If one of you loses his animal or his camel in a deserted land where there is no-one in sight, let him say: "O servants of Allah, help me! (yâ 'ibâd Allâh a'înûnî), for verily he will be helped."
Al-Zahawi said in al-Fajr al-Sadiq, a book he wrote in refutation of Wahhabism:
<<It is not said that all that is meant by the "servants of Allah" in the hadiths cited above are only angels, or Muslims among the jinn, or men of the realm of the invisible: for all of these are living. Hence, the hadith would not give evidence for asking aid from the dead, but this is not the case. We mention this because there is nothing explicit in the hadith whereby what is meant by "servants of Allah" are the categories we mentioned above and nothing else. Yet even if we were to concede this, the hadith would still be a proof against the Wahhabis from another standpoint, and that is the calling on someone invisible. The Wahhabis no more allow it than the calling on the dead.>>
Al-Shawkani also allows the calling on someone invisible: "In the hadith (of a`inu) there is evidence that it is permissible to ask help from those one does not see among the servants of God, whether angels or good jinn, and there is nothing wrong in doing it, just as it is permissible for someone to seek the help of human beings if his mount becomes unmanageable or runs loose."Tuhfat al-Dhakirin p. 155-156.
5. Ahmad relates in his Musnad (4:217) that at the time of the greatest fitna of the Dajjal, when the Muslims will be at their weakest point, and just before `Isa ibn Maryam descends at the time of salat al-fajr, people will hear a caller calling out three times: "O people, al-ghawth (the helper) has come to you!"
6. Ibn Kathir in his history, al-Bidaya wal- Nihaya [7:91, Year 18] narrates that Sayyiduna `Umar radi Allahu anhu sought help and relief from drought and famine in Madina by writing to `Amr ibn al-As and Abu Musa al-Ash`ari in Egypt and Basra respectively, each with the words, "Yaa ghawth aah li Ummati Muhammad! = Help! Help! for the Community of Muhammad!" If this is not istighaatha and isti`aana then there is no istighaatha and isti`aana.
Al-Zahawi said in al-Fajr al-Sadiq:
<<Al-Subki, al-Qastallani in al-Mawahib al-laduniyya, al- Samhudi in Tarikh al-Madina, and al-Haythami in al-Jawhar al- munazzam said that seeking help with the Prophet and other prophets and pious persons, is only a means of imploring Allah for the sake of their dignity and honor (bi jahihim). The one doing the asking seeks from the One asked that He assign him aid (ghawth) on behalf of the one higher than him. For the one being asked in reality is Allah. The Prophet is but the intermediary means (wasita) between the one asking for help and the One asked in reality. Hence, the help is strictly from Him in its creation (khalqan) and being (ijadan), while the help from the Prophet is strictly in respect to secondary causation (tasabbuban) and acquisition from Allah (kasban).....
<<As for the invocations of common Muslim people in Arabic like: "O `Abd al-Qadir Gilani look at me (Ya `Abd al-Qadir adrikni)!" and "O Ahmad al-Badawi give us support (Ya Badawi madad)!" they belong to the figurative language of the mind just as the application of someone who would say to his food: "Satisfy me!" or to his water: "Quench my thirst!" or to his medicine: "Heal me!" The food does not satisfy, nor does the water quench the thirst, nor the medicine heal. But the One who is the real Satisfier of our hunger, the Quencher of our thirst and the Healer of our ills is Allah alone. The food, the water, the medicine are only the proximate or secondary causes which custom has established on the surface of things by our mind's regular association of them with certain concomitant events.>>
Shaykh Khayr al-Din Ramli in his Fatawa Khayriyya (p. 180-181) was asked about "those who say: O Shaykh `Abd al-Qadir! O Shaykh Ahmad! O Rifa`i! [Give us] something for the sake of Allah (shay'un lillah) O `Abd al-Qadir! and such, at which time they become greatly entranced and experience states that make them jump up and down etc. He answered - Allah have mercy on him: 'Know first of all that among the famous rules that are firmly put to use in the books of the Imams is the rule that matters are judged according to their ends... as taken from the hadith of the Two Shaykhs al-Bukhari and Muslim: Actions are only according to intentions.... and none denies the reality of the Sufis except every ignorant, foolish soul.'"
And Allah knows best.