‘Abdullah ibn al-Mas’ood said about the companions (may Allah be pleased with them all):

أنهم أبر الأمة قلوبا, و أعمقها علوما, و أقلها تكلفا

“They have the most pious of hearts from the Ummah, they are the most profound in knowledge and the fewest in speech.”

Source: Ibn Rajab’s book, “Fadl ‘ilm Salaf ala ‘ilm Khalaf” under the the chapter “al-Ibra laysat bikathratil Kalaam”