Abu Hurayrah (may Allah be pleased with him) reported: The Prophet (may Allah's peace and blessings be upon him) said:
"A man follows the religion (i.e. ways and manners) of his close friend. So, each of you should carefully consider whom he takes as his intimate friend."
Reported by At-Tirmidhi (No. 2378), Abu Dawud (No. 4833) and Ahmad (No. 7685, 8065).
The Prophet (may Allah's peace and blessings be upon him) pointed out that a person resembles his close friend and companion in his ways and habits, and friendship affects morals, manners, and behaviors. Therefore, he instructed us to choose our friends carefully, as a friend guides his friend to Imān (faith), guidance, and goodness, and helps him in this regard.
Lessons
The Hadīth enjoins us to befriend good people and choose them carefully and prohibits us from taking wicked people as friends.
He specifically mentioned the friend and not the relative because a person chooses his friends, but has no choice concerning his brothers and relatives.
A person should think well before taking anyone as a friend.
A person’s religious commitment is strengthened by accompanying the believers and is weakened by accompanying sinners.
Explanation in Arabic
بَيَّنَ النبيُّ صلى الله عليه وسلم أنَّ الإنسانَ يُشابه صديقَه وصاحبَه الخالصَ في سيرته وعادته، وتؤثر الصداقة في الأخلاق والسلوك والتصرفات، ولهذا أرشد إلى حسن اختيار الصديق؛ لأنه يَدلُّ صديقَه على الإيمان والهدى والخير، ويكون عونًا لصاحبه.
الأمر بصحبة الأخيار وانتقائهم والنهي عن صحبة الأشرار.
خص الصديق دون القريب؛ لأن الصاحب أنت مَن يختاره، أما الأخ والقريب فليس لك فيه اختيار.
اتِّخاذ الصحبة لا بد أن يصدر عن تفكُّر.
المرء يُقوِّي دينه بِصُحبة المؤمنين ويُضعفه بِصُحبَة الفاسقين.