Even though this may spring from good intentions, one is duty-bound to follow the truth: what is sound is sound and what is weak is weak, and the virtues of good deeds can be attained without validating weak reports.
It is true that the Prophet ﷺ instructed anyone who met Oways al-Qarani to ask him to supplicate for him, yet this directive was unique to Oways alone. He was a man of exemplary devotion to his mother, and Allah—the Exalted—willed to elevate his name in this world before the reward of the Hereafter.
For that reason the Prophet ﷺ never told anyone to ask another person to pray for him, even though there were those superior to Oways. Abū Bakr, beyond doubt, was better than Oways, and many other Companions surpassed him by virtue of their companionship; yet the Prophet ﷺ never instructed anyone to seek the prayers of another.
The correct view, therefore, is that no one should request a personal supplication from someone else, even if he is a righteous man, because such a practice is not part of the Prophet’s guidance nor that of his rightly-guided successors. However, if the request concerns a general supplication—such as asking a pious person to pray for rain or for the lifting of tribulations from the people—there is no harm in that, for the benefit is directed to others, just as when you solicit money on behalf of a poor person, you are neither blamed nor reproached.
As for the Prophet ﷺ himself, the Companions’ asking him to pray for them was among his unique privileges. They would beseech him to invoke Allah on their behalf. For example, when the Prophet ﷺ spoke of the seventy thousand who will enter Paradise without reckoning or punishment, ʿUkkāsha ibn Miḥṣan rose and said, “Pray to Allah that He make me one of them.” The Prophet replied, “You are one of them.” Then another man stood up