This verse describes one of the offerings made at the dedication of the Tabernacle by leaders of the 12 tribes, and is part of the longest chapter in the first five books of the Bible. Each of the 12 tribe leaders brought identical sacrifices to show their dedication to the Lord, and to praise and honor Him for blessing them through Moses (recorded in the previous chapter of Numbers).
For modern believers, this kind of physical act of sacrifice seems alien. In this day and age, who would bring animals and precious objects to a modern Christian church as any kind of offering to God? Indeed, since the practice of sacrificing to atone for sin has been rendered unnecessary by Jesus, this kind of voluntary material tribute to God feels weird.
This does not mean, however, that we are exempt from thanking God. Just because we don’t bring our best plates and lambs to the altar anymore doesn’t mean we’re cleared to treat God like Santa Claus and just ask Him for things without being grateful. Yet many times we do just that–we cry out to Him only in times of sorrow or need. In times of health and happiness, sometimes we forget to tell God “Good job;” we forget to recognize how He protects us, and to praise Him for prayers answered.
Praising is just as important as praying. It’s not that God needs our praise, but that we need to praise Him in order to remember all that God has done for us, all the times He has taken care of us. We bring the sacrifice of praise, as this hymn states; instead of items, we bring our gratitude and humble hearts before God, and we let the memories of God’s faithfulness develop our trust in Him. Our praise and gratitude are literally the best things we can offer God today.