That Christ may dwell in your hearts by faith - see the notes, Ephesians 2:22. Expressions like this often occur in the Scriptures, where God is said to dwell in us, and we are said to be the temples of the Holy Spirit; see the John 14:23, note; 1 Corinthians 6:19, note.
That ye being rooted - Firmly established - as a tree is whose roots strike deep, and extend afar. The meaning is, that his love should be as firm in our hearts, as a tree is in the soil, whose roots strike deep into the earth.
And grounded - θεθεμελιωμένοι tethemeliōmenoi - “founded” - as a building is on a foundation. The word is taken from architecture, where a firm foundation is laid, and the meaning is, that he wished them to be as firm in the love of Christ, as a building is that rests on a solid basis.
In love - In love to the Redeemer - perhaps also in love to each other - and to all. Love was the great principle of the true religion, and the apostle wished that they might be fully settled in that.