Hazrat Abu Hurairah (radhiyallahu ‘anhu) reports that once, at the time of Fajr Salaah, Rasulullah (sallallahu ‘alaihi wasallam) said to Hazrat Bilaal (radhiyallahu ‘anhu), “O Bilaal! From the actions you carry out in Islam, tell me which action do you have the most hope of it benefiting you in the Hereafter, for last night, I had certainly heard your footsteps before me in Jannah (in a dream which I had seen).”
Hazrat Bilaal (radhiyallahu ‘anhu) replied, “The action I carry out, which I hope will greatly benefit me, is that whenever I make wudhu, at any time of the day or night, I perform salaah after making wudhu (i.e. I perform the salaah of Tahiyyatul Wudhu).”
(Muslim #2458)
In this Hadith, we see that on account of performing Tahiyyatul wudhu, Hazrat Bilaal (radhiyallahu ‘anhu) was blessed with the honour of being in the company of Rasulullah (sallallahu ‘alaihi wasallam) in Jannah in the dream he was shown. Hazrat Bilaal (radhiyallahu ‘anhu) walking in front of Rasulullah (sallallahu alaihi wasallam) will be viewed in the same way as a khaadim (servant) walks in front of his master in order to serve him and see to his wellbeing.