But I say to you, do not swear at all; not by heaven, for it is God’s throne; nor by the earth, for it is his footstool; nor by Jerusalem, for it is the city of the great King.

This powerful statement is found in today’s Gospel passage on the feast of St. Barnabas. It is important to first remember that Our Lord is not forbidding swearing “in truth, justice and judgment; to the honour of God or our own or neighbour’s just defence: but only to swear rashly, or profanely, in common discourse, and without necessity” (Bishop Challoner in his notes on Mat 5:34, DRB). The words “I swear” tend to arise quickly from man’s lips, sometimes even followed by the Name of God. This is the kind of swearing that Jesus is condemning. To swear is to call upon God as one’s witness; while swearing solemnly is sometimes necessary in order to defend oneself, one’s neighbour, or even God Himself, we should never swear rashly or without just cause.

In the second part of this statement, Christ shows the omnipotence of God. Heaven is His throne, earth His footstool, and Jerusalem His city. The use of the word “footstool” here is interesting. It is reminiscent of Psalm 109 (110): “The Lord said to my Lord: Sit thou at my right hand: Until I make thy enemies thy footstool” (Ps 109:1, emphasis added). The Father makes Christ’s enemies His footstool, yet here we see Christ referring to the earth as His footstool. 

A closer study of this verse and its wording reveals a deeper meaning to this statement. In His beautiful prayer for His disciples at the Last Supper, Jesus said that “[t]hey are not of the world, as I also am not of the world” (Jn 17:16). When we have the life of God residing in our souls through sanctifying grace, we are no longer “in the flesh, but in the spirit” (Rom 8:9a). We can no longer truly say that we are of this earth, for we have the Blessed Trinity residing within our very souls through the power of this sanctifying grace. 

Those who do not possess this grace within their souls — either by not yet having received Baptism or by mortal sin — do not enjoy this infinite blessing. They are “of the earth,” for their souls do not possess the life that is supernatural grace: “[F]lesh and blood cannot possess the kingdom of God: neither shall corruption possess incorruption” (1 Cor 15:50; cf. 1 Cor 15:48). These are they whom Jesus calls His “footstool.”

Today is the feast of St. Barnabas, who, along with St. Paul, was greatly instrumental in spreading the Faith in the early days of the Church. Let us ask his intercession today that we too can tirelessly work to spread the Gospel, so that all might come to belong to Christ’s heavenly Kingdom.