Job 22:27

Thou shalt make thy prayer unto Him, and He shall hear thee.

For they make their prayer to God, but never obtain to be listened to, who set at nought the precepts of the Lord, when He enjoins them. Whence it is written, He that turneth away his ear from hearing the law, even his prayer shall be abomination. So long then as Eliphaz believed that blessed Job was not heard, he determined that that person had surely done wrong in his practice. And hence he adds further, And thou shalt pay thy vows.

He that has vowed vows, but is unable from weakness to pay the same, has it dealt to him in punishment of sin, that whilst willing good, the having the power should be taken away from him. But when in the sight of the interior Judge, the sin which hinders is done away, it is immediately brought to pass, that the being able attends upon the vow.

From this contemplation you will get confidence in having recourse to him, and so he then says, "You will ask him." This will not be without result and so the text says, "and he will hear you." Those whom God has heard usually fulfill the promises which they made in praying. So he says, "and you will fulfill your promises," as the sign that you have been heard.