Of the greatness of his government and peace
there will be no end.
He will reign on David’s throne
and over his kingdom,
establishing and upholding it
with justice and righteousness
from that time on and for ever.
The zeal of the Lord Almighty
will accomplish this. (Isaiah 9:7, NIV)
Despite heartily endorsing the “birthday boxing day” (or even birthday week), it turns out that until yesterday, I had never seriously explored the origins of Boxing Day. Probably led astray by older relatives who were joking, I formerly thought that it was merely a day of taking stock (even boxing up the gifts from the previous day!) with the convenient backdrop of a holiday and, with that, a good dose of sport. Compared to Christmas Day, I considered it an unimportant day: business as usual; the previous day’s events largely forgotten.
I have, however, been slightly surprised to find that the origins of Boxing Day are rather different. It more likely goes back to the giving of boxes of gifts from masters to their servants, or from collections to the poor.
Isaiah 9:7 forms the climax to a section, probably datable to the eighth-century BC, in which the prophet Isaiah explains how Israel had ended up in darkness because of her failure to consult God (Isa 8:19-22), but then consoles Israel with the promise of future – although not immediate – light and hope (Isa 9:1-2). The people will rejoice and be at peace because of the coming of an ideal ruler, who is described as a child, a son (Isa 9:3-6). Christian tradition has seen the fulfilment of this figure in the person of Jesus Christ, the Son of God, and so rightly appears on Christmas cards and many social media timelines on 25th December.
Yet, how often do we consider Isaiah 9:7? I believe that it is somewhat overlooked and treated like my previous understanding of Boxing Day compared to Christmas Day. Isaiah 9:6 describes the arrival of the Son, but Isaiah 9:7 portrays the reign of the Son. This is something that truly lasts. There is no end or limit in time or space to the reign of Jesus; it is an eternal one. The now risen and ascended Jesus cannot be boxed; He still holds sway over this world, although it will not be perfect until he returns.
The actual origin of Boxing Day might also apply. The reign of Jesus is characterised by justice and righteousness and we can reasonably extend that to include grace, mercy and compassion. This is based on what we see in the life of Jesus: for instance, his willingness to serve and give his life as a ransom for many (Mark 10:45). Since he humbled himself to death on a cross and defeated death, God raised him up and gave him authority over all creation (Philippians 2:6-11). Ultimately, Jesus reigns; but he created us as his co-regents to rule and to govern over creation. We all probably have more influence than we imagine, and so my encouragement is to see Boxing Day as a day to reflect on the just, merciful, gracious, and compassionate nature of God, and to seek to follow this example. At the same time, we realise that Jesus holds ultimate authority, but is unfailingly gracious towards those who love him and choose to listen to His voice.
For these reasons, I now see Isaiah 9:7 as a good verse for Boxing Day reflection, amid other good activities in God’s creation – like sport.
 My highly academic, in-depth research took me to Wikipedia and this article: https://www.thespruce.com/what-is-boxing-day-435060
 The identity of this figure is debated among scholars. I can’t claim to be an expert in this area but I have found John Goldingay’s remarks helpful on the subject. In his view, Isaiah 9:6-7 is ‘a judgement and a statement of hope based on what we know of the Jesus rather than an exegetical judgment about the meaning of this passage’ (Isaiah, 1995, p.72). In other words, we can see Jesus in the remark, but whether the original prophecy at that precise time referred to Jesus is less certain. Goldingay argues elsewhere that it is used to describe God, see: idem, “The Compound Name in Isaiah 9:5(6)”, CBQ 61 (2) (1999), 239-44.
 This verse is more likely alluded to in the New Testament in Luke 1:32-33 when the angel Gabriel speaks to Mary: “He will be great and will be called the Son of the Most High. The Lord God will give him the throne of his father David, and he will reign over Jacob’s descendants for ever; his kingdom will never end.” (NIV)