There is no ‘start’ and ‘end’ to Prayer

“Whoever is used to praying only at such time as the knee is bent, prays very little. But whoever, even on bended knee, is distracted by any sort of wandering heart, prays not at all. And for this reason, it behoves us even before the time of prayer to be such as we would wish to be found at prayer. For it is necessary that the mind be formed at the time of its supplication by its previous condition, and by those thoughts on which it had tarried before prayer its prayer is either elevated to heavenly things or else plunged into earthly things.” St. John Cassian recording Abba Isaac in Conferences, 10.14.2.