Nine-tenths of all created beings are said to be angels who are formed of light. Their rank is stationary, and each is content with the position he occupies. Their one desire is to love and to know God. Whatever he commands they do. "All beings in the heaven and on the earth are His: and they who are in His presence disdain not His service, neither are they wearied: they praise Him day and night." (Sura xxi. 19, 20.) They are free from all sin.[125] It is true that they did not wish for the creation of Adam, and this may seem like a want of confidence in God. It is said, however, that their object was not to oppose God, but to relieve their minds of the doubts they had in the matter. Thus "when the Lord said to the angels, 'Verily, I am about to place one in my stead on earth,' they said: 'Wilt Thou place there one who will do ill therein, and shed blood when we celebrate thy praise and extol thy holiness.' God said: 'Verily I know what ye know not.'" It is true that Iblis was disobedient, but then he belonged not to the angelic order but to that of the jinn. "When we said to the angels, 'prostrate yourselves before Adam,' they all prostrated themselves save Iblis, who was of the jinn, and revolted from his Lord's behest." (Sura xviii. 48.) (See also Sura ii. 33.) Angels appear in human form on special occasions, but usually they are invisible. It is a common belief that animals can see angels and devils. This accounts for the saying, "If you hear a cock crow, pray for mercy, for it has seen an angel; but if you hear an ass bray, take refuge with God, for it has seen a devil." {141} The angels intercede for man: "The angels celebrate the praise of their Lord and ask forgiveness for the dwellers on earth." (Sura xlii. 3.) They also act as guardian angels: "Each hath a succession of angels before him and behind him who watch over him by God's behest." (Sura xiii. 12.) "Is it not enough for you that your Lord aideth you with three thousand angels sent down from on high?" (Sura iii. 120.) "Supreme over His servants He sendeth forth guardians who watch over you, until when death overtaketh any one of you our messengers take his soul and fail not." (Sura vi. 61.) In the Traditions it is said that God has appointed for every man two angels to watch over him by day, and two by night. The one stands on the right hand side of the man, the other on his left. Some, however, say that they reside in the teeth, and that the tongue of the man is the pen and the saliva of the mouth the ink.[126] They protect the actions of men and record them all whether good or bad. They are called the Mua'qqibat, _i.e._, those who succeed one another. They also bear the name of Kiram-ul-Katibin, "the exalted writers." They are referred to in the Quran. "Think they that we hear not their secrets and their private talk? Yes, and our angels who are at their sides write them down." (Sura xliii. 80).