Abd Allah ibn Masud: No praisers of Allah were there among whom the Holy Prophet (PBUH) was not present; and no prayer performers were there that the Holy Prophet (PBUH) would not say more prayers than all of them.
Imam Ali (AS) while engaged in battle in Siffin he was also taking into consideration the sun movement too. Ibn Abbas asked him: O Amiral-Muminin! What are you doing? His Holiness (AS) replied: I am looking to see when the noon-time comes up to say my prayers. Ibn Abbas told the Imam (AS): Is it now time for prayers?! Battle has thwarted us from prayers. The Imam (AS) said: Why do we fight with them?! Our conflict with them is just over [performing] prayers.
It is related that: when the prayers time came, Ali’s (AS) face would turn pale and he would start trembling. When he was asked what had become of him, he replied: Now has come the time to pay back the trust (amanah) that Allah, the Almighty offered it to the heavens and the earth and the mountains, but they refused to undertake it, and man undertook it [cf.33: 72, 73], and I, with all my helplessness, do not know whether I can undertake this trust.
The Messenger of Allah (PBUH): As for my daughter Fatima (AS) would stand before her Exalted Allah, while her light was as brilliantly evident for the heavens as the stars were for the people on earth, and Allah would say to the angels: O My angels! Look how My slave-maid, Fatima (AS), the princess of My slave-maids, is trembling before me out of fearing Me, and is whole-heartedly worshipping me.
Imam Sadjad (AS): Hassan ibn Abi Talib (AS) was the most devoted the most abstemious, and the most virtuous of all in his own era; whenever he went on Hajj, he would go on foot and sometimes he would travel barefooted. Whenever he remembered death and grave he would weep; and as he remembered the Resurrection and being revived drops of tears would flow down his cheeks; when passing the Sirat would come to his mind he would start crying; whenever he remembered the presentation [of actions] to the Almighty Allah, he would let out a yell which made him unconscious; and when he stood up to say prayers his body would start trembling; when he remembered Paradise and Hell his body would get twisted restlessly as someone stung by a snake; and would ask for Paradise from Allah, and took refuge in Him from the Hell Fire. Any time he read the phrase, O those who believe, from the Qur’an he would say: Here I am, O Allah! Here I am. He was always seen glorifying and praising Allah.
Sabzivari in Jami al Akhbar: Whenever Hussein ibn Ali (AS) performed ablution, his face would turn pale and his joints would start trembling. When being asked the reason, he would answer: It is true for someone who stands before the Almighty Allah to turn pale and his joints start to tremble.
Imam Baqir (AS): When my father, Ali ibn al-Hussein (AS) was saying prayers, his skin would wrinkle, his face would turn pale, his body would tremble, and his hair would stand on end, and while drops of tears were flowing down his cheeks he would say: If a servant knows to whom he is supplicating, he would not give up his prayers.
Abu Ayyub: Whenever Imam Baqir (AS) and Imam Sadiq (AS) stood in prayers their faces would at times turn red and at time pale, as if they were talking to someone they witnessed.