احسن الله إليكم Ustadh, in the foundational Dawrah, the following was mentioned: he who goes away from Jama'ah by an inch, he has taken off the handhold of Islam, may I ask you to expand on this, moreover expl it to me? بارك الله فيكم

The hadith is authentic, graded ṣaḥīḥ by al-Albani raḥimahullāh, and Imam Ibn Baz raḥimahullāh explained it in his sharh of Kitab Fadl al-Islam. Take it step by step. "The jamaah" is not any random group; it is the body of the Muslims holding to the Book and the Sunnah upon the way of the Companions. Ibn Baz stressed that the Muslims are one, that a person must not rally to the call of pre-Islamic partisanship (tribe, land, faction) but only to Islam and iman. "The handhold of Islam", in the word ribqah, is the tie put around an animal's neck to keep it held, so whoever walks away from the jamaah, even by a handspan, has slipped that tie of the covenant of Islam off his own neck. But look at the end of the hadith, because it changes everything: "unless he returns." This is not a final expulsion. Whoever leaves and then comes back to the jamaah, the tie of Islam returns to him. So the hadith shows two things together: how serious it is to break away from the united body of the Muslims upon the truth, and that the door of return is always open. Hold to the jamaah, and if a person slips, let him hurry back.