The sacrificial system, committed to Adam, was also perverted by his descendants. Superstition, idolatry, cruelty, and licentiousness corrupted the simple and significant service that God had appointed. Through long intercourse with idolaters the people of Israel had mingled many heathen customs with their worship; therefore the Lord gave them at Sinai definite instruction concerning the sacrificial service. After the completion of the tabernacle He communicated with Moses from the cloud of glory above the mercy seat, and gave him full directions concerning the system of offerings and the forms of worship to be 365 maintained in the sanctuary. The ceremonial law was thus given to Moses, and by him written in a book. But the law of Ten Commandments spoken from Sinai had been written by God Himself on the tables of stone, and was sacredly preserved in the ark.

Offersystemet, som var blevet overdraget til Adam, blev forvansket af hans efterkommere. Overtro, afgudsdyrkelse, grusomhed og ryggesløshed forvanskede den enkle og betydningsfulde tjeneste, som Gud havde anvist. Gennem langvarigt samkvem med afgudsdyrkere havde Israels folk flettet mange hedenske skikke ind i deres gudsdyrkelse. Derfor gav Gud dem på Sinaj tydelig undervisning om offertjenesten. Efter tabernaklets fuldførelse talte han til Moses fra skyen over sonedækket, hvor hans herlighed kom til syne, og gav ham en fyldestgørende vejledning om offersystemet og den gudstjenesteform, som skulle gælde i helligdommen. På den måde fik Moses ceremoniloven, som han skrev i en bog. Men de ti bud, der blev forkyndt fra Sinaj, havde Gud selv skrevet på stentavlerne, og de blev med hellig omhu opbevaret i arken.