Hisham bin Hassan (may Allah have mercy on him) said: We were with Muhammad bin Sirin (may Allah have mercy on him) when a man stood up and recited: 'And whoever kills a believer intentionally, his recompense is Hell' [Surah al-Nisa: 93], until he completed the verse. Ibn Sirin (may Allah have mercy on him) became very angry and said: Have you not heard this saying: 'Indeed, Allah does not forgive that partners be associated with Him, but He forgives what is less than that for whom He wills' [Surah al-Nisa: 48], that Allah forgives every sin besides shirk? Then he said: Get up and leave my gathering. And he was put out from there.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النفقات / 15831