Man Lā Yaḥḍuruh al-Faqīh #910Hadith.912 - Imam (as) said:
"Whoever does not eat meat for forty days, their temperament may deteriorate, and if their temperament becomes...
Al-Kāfi #1208“Abu ‘ Abd Allah (a.s.), has said, ‘Meat grows meat and one who does not eat meat for forty days his manners change to worse, you must say...