In celestial mechanics Mercury completes one cycle every 116 days. This means that in one solar year, Mercury will complete 365÷116 or 3.14 cycles. Because of this decimal interval the ancients observed Mercury in 7-year periods. Every 7 years, Mercury completes 22 conjunction cycles (because pi is approximately equal to 22÷7, this ratio is extremely precise with only an hour difference!).
"¡Oh profundidad de las riquezas de la sabiduría (sophia) y de la ciencia (gnwsiV, gnosis) de Dios! ¡Cuán incomprensibles son sus juicios, e inescrutables sus caminos!" (Romanos, 11: 33).