Riyad as-Salihin, Book 18, Hadith 1592 (In-Book) ⓘ

Abu Ayyub Al-Ansari (May Allah be pleased with him) said: The Messenger of Allah said, "It is not lawful for a Muslim to desert (stop talking to) his brother beyond three nights, the one turning one way and the other turning to the other way when they meet, the better of the two is one who is the first to greet the other."[Al-Bukhari and Muslim].

وعن أبي أيوب رضي الله عنه أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏ "‏لا يحل لمسلم أن يهجر أخاه فوق ثلاث ليال‏:‏ يلتقيان، فيعرض هذا ويعرض هذا، وخيرهما الذي يبدأ بالسلام‏" ‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏‏.‏