Some lessons we learn from this hadeeth
1) Since Abu Huraira (r.a) was in the streets in the condition of Junub, scholars have said that It is not compulsory to immediately take ghusl after being in a state of sexual defilement however as per other ahadeeth, the scholars have deemed it mustahhab.
2) The asking of the prophet “Where have you been?” shows that it is against the proper adab to leave someone who is in your company without seeking his permission or notifying him.
3) The understanding of Abu Huraira (r.a) teaches us that it is preferable to give respect to esteemed personalities such as scholars and to be clean and tidy in their presence
4) the expression “Subhanallah” was said by the Prophet sallalahu `alayhi wa sallam out of amazement and some scholars have also said it was an expression questioning something
5) As for the issue of the believer never becoming impure then this is a general statement and is taken in terms of essence (dhaat). This does not mean that a believer does not need to take ghusl after janaabah or that he doesn’t become impure after having fallen in a urine pool.
Also some ulema have taken this statement to apply that in essence, a believer whether dead or alive remains pure.