The word “Consecrate” in its Greek origin means to sanctify. Thus when the Lord said to Moses: “Consecrate to Me all the firstborn, whatever opens the womb … it is Mine.” (Ex 13:2), He meant that those firstborn should be sanctified to Him and not for any other purpose. The firstborn males used to devote themselves to the service of the Lord before Aaron and his offspring. The firstborn of cattle were also offered as a sacrifice.
Sacred garments for the service of priests were consecrated to God. In this, the Lord said to Moses: “So they shall make holy garments for Aaron your brother and his sons, that he may minister to Me as priest.” (Ex 28:4).
Altar vessels are sacred for the Lord, devoted to His service, and were not use for any other purpose. Sanctifying a house for the Lord is to devote it to Him and cannot be used for any other thing but the worship of the Lord: “My house shall be called a house of prayer.” (Matt 21:13).
Some may ask: What does the Lord mean by His words to His disciples: “And for their sakes I sanctify Myself.” (John 17:19). He means that He devotes Himself to them and the church for He came to redeem her.
Sacraments are the Lord’s appropriations, they belong to the Lord alone and to no one else. They are consecrated to the Lord in the same way as the firstborn were. As the Lord says through the Prophet Ezekiel: “There I will require your offerings and the firstfruits of your sacrifices, together with all your holy things.” (Ezek 20:40). About the first fruits of every fruitful tree, He says: “But in the fourth year all its fruit shall be holy, a praise to the Lord.” (Lev 19:24). Their fruit was for the Lord and was given to the Lord’s priests. (Ezek 44:30).
It was said that the money going into the Lord’s money box in the sanctuary “are consecrated to the Lord; they shall come into the treasury of the Lord.” (Josh 6:19) to be devoted to the Lord.
In the same way, days were consecrated or devoted to the Lord.
To “Remember the Sabbath day, to keep it holy.” (Ex 20:8), to devote the day to the Lord, namely not performing any work for it is for the Lord. In the same way, we should consecrate to the Lord all His feast days on which holy gatherings are held, to cease from work and devote to the Lord. (Lev 23:3, 7, 8, 21, 25, 31, 36).
Thus sanctification of fasting is to consecrate it to the Lord.
Days of fasting are sacred, and are devoted to the Lord. They do not belong to the world but to the Lord’s as a sanctification to Him.
That is why God’s inspiration clarified this meaning when He said “Consecrate a fast, Call a sacred assembly” (Joel 1:14, 2:15), because a “sacred assembly” is fit for the consecration of the fast to the Lord, devoting it to Him.
However, what can you do if it is not possible for you to devote all your time to the Lord, and withdraw from your official work?
Withdraw as much as you can to devote yourself to God. However, if, despite your efforts, time becomes limited, devotion takes on another meaning:
At least, aim to devote the fast for the Lord.
In this way, it becomes a sacred fast, for it is consecrated to God as far as its aim and approach are concerned. In this we comprehend the dual meaning of the word sacred namely pure for it is to the Lord.