One of the memorable moment of the retreat was when I was reading about Moses and the blazing bush and I looked up and saw a cloud with silver lining and a orange blaze behind the cloud. For a moment, it looked like a burning bush or flash of an angel’s wing.
I later found out that it was an iridescent cloud, apparently a rare phenomenon
If parts of clouds have small droplets or crystals of similar size, their cumulative effect is seen as colors. The cloud must be optically thin, so that most rays encounter only a single droplet. Iridescence is therefore mostly seen at cloud edges or in semi-transparent clouds, and newly forming clouds produce the brightest and most colorful iridescence. When a thin cloud has droplets of similar size over a large extent, the iridescence takes on the structured form of a corona, a central bright disk around the sun or moon surrounded by one or more colored rings. In one instance a lunar corona was observed, with the iridescent cirrus cloud 11–13.6 km (36,000–45,000 ft) above the mean sea level at a temperature of −70 °C (−94 °F). The pure corona was 9.5 km (31,000 ft) above the mean sea level, at a temperature of −60 °C (−76 °F).
Whatever it was, I am thankful for God for the glimpse. It was like a chariot of fire!