Mukhtasar Bukhari

Narrated from Sayyiduna Abu Sa'id Khudri, may Allah be pleased with him, that in the time of the Noble Prophet, peace and blessings be upon him, there were some hypocrites who outwardly became Muslims. When the Messenger of Allah, peace and blessings be upon him, would go out for jihad, they would stay behind (in Madinah) and would be happy at not going with the Messenger of Allah, peace and blessings be upon him. Then when he, peace and blessings be upon him, would return from jihad, they would make various excuses and swear oaths (that due to such and such reasons we could not go), and they liked to be praised for deeds they had not done. So this verse was revealed about them: "Those who rejoice for what they have done, and love to be praised for what they did not do..."