Once we have completed our prostrations, the next part of the prayer is to sit and recite the تشهُّد tashahhud, the first part of which is التحيات لله commonly translated as, “All salutations are for Allah.”
The word تحيات tahiyyaat is the plural of the word تحية which refers to a veneration. The ال prefixed to the word indicates that absolutely all venerations are for Allah, and thus the phrase signifies that every form of veneration, both in a general or in a complete sense, is for Allaah. Our veneration of Him stems from our own need of Him, not due to His need for veneration.
Thus, when we say التحيات لله what we are essentially saying is, “I dedicate each and every form of veneration to You alone, O Allah, both specifically towards you, and in general, for You are the only One worthy of such veneration, and we are the ones in need of You.”