Planets in houses · Kendra
Shani in the 1st house
Saturn · Tanu Bhava
Shani is the karaka (significator) of discipline, career, endurance and longevity. The 1st house, called Tanu Bhava, shows self, body and personality. When Shani sits here, these matters take on its colour.
A malefic in the Lagna gives strength of will and drive, but can make one impatient or harsh and needs care for health.
The 1st house is a kendra (angular house), a pillar of the chart, so a graha here shows its results openly and strongly.
The 1st house is opposite to where Shani gets directional strength, so it loses some power here.
Shani gives its best results here when it is exalted in Tula, in its own sign (Makara and Kumbha) or in a friendly sign, and when it is not combust.
Results are weaker if Shani is debilitated in Mesha, combust, or afflicted by malefics.
In transit (gochar)
When Shani transits the 1st house counted from your Moon sign, the period traditionally needs more care.
A single placement is never read alone: sign, aspects, conjunctions, dasha and the whole chart change the outcome.