Another example is the statement of a man who said:

“I frequently invoke blessings upon you. How much of my supplication should I devote to invoking blessings upon you?”
He replied, “As much as you wish.”
The man asked, “A quarter?”
He replied, “As much as you wish, but if you increase it, that is better for you.”
The man asked, “Half?”
He replied, “As much as you wish, but if you increase it, that is better for you.”
The man asked, “Two-thirds?”
He replied, “As much as you wish, but if you increase it, that is better for you.”
The man said, “I shall devote all my supplication to invoking blessings upon you.”
He replied, “Then your concerns will be taken care of, and your sins will be forgiven.”

This was narrated by Ahmad in his Musnad, al-Tirmidhī, and others. It has been discussed at length in Answers to the Baghdad Questions. This man had a supplication that he would regularly make. If he replaced it with invoking blessings upon the Prophet, may Allah bless him and grant him peace, Allah would take care of whatever concerned him in this world and the Hereafter. For whenever he invokes blessings upon him once, Allah blesses him ten times. If he were to supplicate for individual believers, the angels would say, “Amen, and may you receive the same.” His supplication for the Prophet, may Allah bless him and grant him peace, is all the more deserving of that response.

Whoever says to another person, “Supplicate for me—or for us,” intending that the person asked should benefit from supplicating, that he himself should also benefit from asking him to do so, and that the person should carry out what he has been asked to do—just as he would ask him to perform any other good deed—is following the Prophet, may Allah bless him and grant him peace, and taking him as his example. This is not a less preferable form of asking.

But if his sole intention is to have his own need met, without intending to benefit the other person or show him kindness, then he is not following the Messenger or taking him as his example in this matter. Rather, this is a less preferable form of asking: it is better to leave it aside and turn to Allah and His Messenger than to turn to a created being and ask him.

All of this concerns permissible, religiously sanctioned requests made of the living.