What is the meaning of there being none but Allah the Almighty in the servant's heart, and Ibrahim's saying, "And grant me a reputation of truth among later generations," and was that among the permissible desires?

Safety of the heart means not being attached to other than Allah, and that Allah is the most beloved of things to a person. The sign of a sound heart is its recourse to Allah and its tranquility in Him, for there is no life, no success, no bliss, and no joy for the heart except through Allah's pleasure, closeness to Him, and intimacy with Him. The remembrance of Allah is the strength and nourishment of the heart, and love for Him and yearning for Him are its life, bliss, and joy. Attachment to other than Allah is a blight upon the heart.

Among the corruptors of the heart is attachment to other than Allah, because it severs the heart from its interests and happiness. If the heart becomes attached to other than Allah, Allah abandons it to that to which it has become attached and forsakes it. Thus, it neither attains its share from Allah nor reaches what it hoped for from that to which it was attached. The most forsaken of people is he who is attached to other than Allah, for what he misses in terms of interests and happiness is greater than what he gains. The example of one attached to other than Allah is like one seeking shade from heat and cold under a spider's web, which is the frailest of houses.

Asking a question similar to the request of Ibrahim (peace be upon him) for a truthful tongue is permissible if the intention is for the remembrance to remain so that people may follow his example in good deeds, and for the action to be sincere.