Anas bin Malik reported,

The Prophet of Allah ﷺ had Muaz bin Jabal riding behind him on his mount.He said, "Muaz."Muaz replied, "At your service, Messenger of Allah, and at your pleasure."He said again, "Muaz."Muaz replied, "At your service, Messenger of Allah, and at your pleasure."He said a third time, "Muaz."Muaz replied, "At your service, Messenger of Allah, and at your pleasure."The Prophet said, "There is no servant who testifies that there is no god but Allah and that Muhammad is His servant and Messenger except that Allah forbids the Fire from touching him."Muaz asked, "Messenger of Allah, shall I not inform the people of this so they may rejoice?"He replied, "Then they will rely on it alone."Muaz disclosed it only at the time of his death, fearing the sin of withholding knowledge.

Azami 1176

Sahih

عن أنس بن مالك

أن نبي الله ﷺ، ومعاذ بن جبل رديفه على الرحل قال: يا معاذ قال: لبيك رسول الله وسعديك. قال: يا معاذ قال: لبيك رسول الله وسعديك. قال: يا معاذ قال: لبيك رسول الله وسعديك. قال: ما من عبد يشهد أن لا إله إلا الله، وأن محمدا عبده ورسوله إلا حرمه الله على النار. قال: يا رسول الله، أفلا أخبر بها الناس فيستبشروا؟ قال: إذا يتكلوا. فأخبر بها معاذ عند موته تأثما.

الأعظمي 1176صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Knowledge
Chapter
Encouragement to seek knowledge
Section
Command for the scholar to speak to people according to their understanding
Numbering
Jami al-Kamil 1176 (2nd edition)
Azami 1176