The Thau that is mentioned in the first reading translates to the Greek letter 'T' which was adopted by St. Francis of Assisi as his personal symbol of the cross. Today's reading brings home the significance of that symbol, since we all want to be marked by a sign of Christ. Today is also the feast of St. Clare, a close friend and contemporary of St. Francis. These two young people turned their back on their life of comfort and material wealth to serve the Lord.
One more thing: Jesus' sermon today on brotherly love brings to life his acknowledgment that there would be conflict within families. He gives us a guide to sort out those conflicts with love and wisdom. But in the end, he doesn't condone being a doormat. If your brother (or sister) doesn't ever see eye to eye with you, despite your very best effort to resolve the conflict, then some things will just have to be sorted out in heaven. Christ tells us today, however, to do our best to make peace.
Prayer: Lord Jesus, thank you for showing me how to live with my fellow man. Give me the love, fortitude and perseverance to work out conflict with my brother. Help me to teach my children to make peace with each other. In your name I pray, Amen. St. Clare, pray for me.