Mahmud ibn Labeed reported: The Messenger of Allah, peace and blessings be upon him, said, “If Allah loves a people, then he afflicts them with trials. Whoever is patient has the reward of patience, and whoever is impatient has the fault of impatience.”

Source: Musnad Ahmad 23122

Grade: Sahih (authentic) according to Al-Albani

عَنْ مَحْمُودِ بْنِ لَبِيدٍ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِذَا أَحَبَّ اللَّهُ قَوْمًا ابْتَلَاهُمْ فَمَنْ صَبَرَ فَلَهُ الصَّبْرُ وَمَنْ جَزِعَ فَلَهُ الْجَزَعُ

23122 مسند أحمد بَاقِي مُسْنَدِ الْأَنْصَارِ

1706 المحدث الألباني خلاصة حكم المحدث صحيح في صحيح الجامع

Narrated Busr bin Said (Radi-Allahu 'anhu):

that Zaid bin Khalid sent him to Abi Juhaim to ask him what he had heard
from Allah's Apostle (Sallallahu 'Alaihi Wa Sallam) about a person passing
in front of another person who was praying. Abu Juhaim replied, "Allah's
Apostle said, 'If the person who passes in front of another person in
prayer knew the magnitude of his sin he would prefer to wait for 40 (days,
months or years) rather than to pass in front of him.' Abu An-Nadr said, 'I
do not remember exactly whether he said 40 days, months or years.' "

Bukhari Vol. 1 : No. 489