After a person realises that only Allah can respond to his du’a the logical consequences that he prays only to Allah. This is the essence of tauhid al-‘amali, or the 'tauhid of one’s actions.'
The proof for this condition is found in many Qur’anic verses and ahadith. Some of these verses are:
"And Verily the mosques are for Allah Alone, so do not call upon anyone besides Him." [Surah al-Jinn: 18]
"Will you call upon other than Allah if you are truthful?” [Surah al-An’am: 40]
"Those whom you call upon besides Allah are slaves like yourselves.” [Surah al-A’raf: 194]
"And those who you ask besides Him can neither come to your aid, nor can they help themselves.” [Surah al-A’raf: 197]
The meaning of the phrase, '...besides Allah ...' includes everything that is worshipped besides the Creator, from lifeless objects like idols or the sun, trees, animals, men, a pious person, a prophet, an angel, or any other object besides.
Another proof is the advice that the Prophet (Peace be upon him) gave to Ibn ‘Abbas one day, when he (Peace be upon him) said:
“O slave! Guard (the duties of) Allah and He will guard you! Guard (the duties of) Allah and you will find Him in front of you! And when you ask, ask only from Allah, and when you seek any help, seek help only from Allah!”
 Authentic, narrated by Abu Dawud, Ahmad, al-Tirmidhi, al-Hakim from Ibn (Abbas, and authenticated by al-Albani in Sahih al-Jami #7957.
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