JAAFAR BIN MOHAMMAD, from his father, from ALI BIN HUSAIN (ASWS) who said:
ALLAH (SWT) has made five religious duties mandatory, and everything that ALLAH (SWT) makes mandatory is beautiful: Salaat, Zakaat, Hajj, Siyaam, and our Wilayat.
People obeyed ALLAH (SWT) in the first four and ignored the fifth one. I swear to ALLAH (SWT) that the first four are not complete without the fifth.
(Ref : Bihar Al-Anwar 23:105)