Al-Hasan Al-Basrî – Allah have mercy on him – said:

Faith (îmân) is not by embellishment or wishful thinking, but it is what settles in the heart and is verified through your works. Whoever says good but does not do good will have his words compared to his deeds by Allah. Whoever says good and does good will have his words raised by his deeds. This is because Allah ‘azza wa jalla said:

To Him ascends the good word, and the righteous deed raises it. [Sûrah Fâtir: 10]

Ibn Battah in Al-Ibânah Al-Kubrâ Vol. 3 p120, and Al-Khatîb Al-Baghdâdî in Iqtidâ’ Al-‘Ilm Al-‘Amal no.56.