Hadithcore
Riyad as-Salihin, 220

Ibn 'Umar (May Allah bepleased with them) reported:

Messenger of Allah (ﷺ) said, "A believer continues to guard his Faith (and thus hopes for Allah's Mercy) so long as he does not shed blood unjustly". <b>[Al-Bukhari]</b>.

وعن ابن عمر رضي الله عنهما قال‏:‏ قال رسول الله صلى الله عليه وسلم‏:‏ “ لا يزال المؤمن في فسحة من دينه ما لم يصب دمًا حرًا‏"‏ ‏(‏‏(‏رواه البخاري‏)‏‏)‏‏.‏

References1 variant
In-Book Reference
Introduction, Hadith 220
Sharh · explanationclick to expand
<b>Guidance from the Hadith:</b><br> 1) Shedding blood unlawfully is from the major sins.<br> 2) transgressing against the Muslims’ blood is one of the gravest forms of injustice and entails corrupting the perpetrator’s religiosity.