Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Amr bin Taghlib (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "This is among the signs of the Hour: wealth will become widespread, ignorance will become common, tribulations will emerge, trade will become widespread, and knowledge (that is, reading and writing) will become common."