Wait a minute! Didn't I already meditate on this name at the beginning of February?
No, that was El Qadosh, the Holy God. Qadosh and Qadash might sound almost the same, but there's a subtle difference in meaning. Qadosh is an adjective, meaning holy or sacred, while qadash is a verb, meaning to sanctify or to make holy.
We read in the Bible that God made the sabbath day holy - meaning He consecrated it and set it apart for a specific purpose. We also read in Exodus that the tabernacle, the altar and the priests were "sanctified." But where it gets more radical is when God speaks to the people as a whole, telling them, "I am Yahweh Qadash - the Lord who makes you holy." (Ex 31: 13, Lev 20: 8)
Although it's God who sanctifies, there are also a surprising number of verses where the people are told to,"Sanctify yourselves..." - for example, in Joshua 3: 5, where Joshua tells the people, "Sanctify yourselves" (or consecrate/purify yourselves, depending on your Bible translation) because tomorrow the Lord will do great wonders among you."
That doesn't mean that we can become holy by our own efforts. When we look more closely at those Old Testament verses, we discover that it's more about consecrating ourselves for God's sake and getting rid of anything that would defile us. Sometimes the people were asked to wash their clothes or their body, sometimes they offered sacrifices for sin; they were asked to observe the sabbath and follow dietary restrictions that involved not eating "unclean" animals. It also meant abstaining from certain sexual practices, and getting rid of idols, witchcraft, mildew and other things that would defile them. Interestingly, a few times in the writings of Ezekiel, qadash is simply translated as, "prepare." It's about preparing and purifying ourselves for the Lord.
We have a part to play, but God's part is much bigger. Our part is to recognise and confess sin; God's part is to forgive and cleanse from sin (Greek katharizō, as in 1 John 1: 9) and to make us holy. (Greek hagiazō, as in 1 Cor 6:11 or 1 Thess 5: 23)
The New Testament writer to the Hebrews concludes his letter by reminding them that Jesus shed his blood to "make us holy." (Heb 13: 12) He did His part first, and when we do our part we can enter into the benefit of that. He is still Yahweh Qadash today.