The word sanctify means;

To fulfil obedience towards God’s commandment, which commands a person to separate the Holy things from his/her abode or dwelling.

The Holy things which God commands humanity to give unto Him are as stated below:

marriage, tithe, obedience towards God’s word, offerings, Holy communion, keeping God’s commandments, keeping God’s season on God’s calendar, prayer, baptism etc,

these are the things which has the ability to sanctify a person’s character or life.

Sanctify – to set apart as or declare holy; consecrate.

synonyms:consecrate, make holy, make sacred, bless, hallow, set apart, dedicate to God, anoint, ordain, canonize, beautify.

make legitimate or binding by a religious ceremony.

“their love is sanctified by the sacrament of marriage”

synonyms:purify, cleanse, free from sin, absolve, unburden, redeem, wash someone’s sins away;

Numbers 5:9
Every offering of all the holy things of the children of Israel, which they bring to the priest, shall be his.

Exodus 28:38
So it shall be on Aaron’s forehead, that Aaron may bear the iniquity of the holy things which the children of Israel hallow in all their holy gifts;

and it shall always be on his forehead, that they may be accepted before the Lord.