Let us pray (in silence) [that we may be prepared]
Stir up, O Lord,
the wills of your faithful people
that, richly bearing the fruit of good works,
they may by you be richly rewarded;
through Jesus Christ our Lord
who is alive with with you and the Holy Spirit,
one God now and for ever.
NZPB p. 641c
This was one of the daily prayers in the Gregorian Sacramentary. The Latin word translated "stir-up" is "excita". In the Sarum Missal the collects of the first, second, and fourth Sundays of Advent also began with this word. This refers both to God's action and our wills, just as the fruit refers to both God's work and ours.
The Sunday before Advent was known as Stir-Up Sunday. It is traditionally the time to get the Christmas pudding (a fruit cake - see collect) made, allowing plenty of time for the flavours to develop before it's enjoyed on Christmas Day. Whilst once it felt surprising to be thinking about Christmas this early - in this consumer-driven society it is more difficult to ignore Christmas already for sale in October!