Reference: al-Hilyah – Volume 8, Page 270
Wakee’ ibn al-Jarraah said:
Whoever is not concerned with [preparing for] the prayer before its time, then he has not dignified or venerated it.
And Wakee’ [also] said:
Whoever is negligent and misses the initial takbeer [upon beginning the congregational prayer], then wash your hands of him (i.e. have nothing to do with him).