This page explains how to find the Yah Rin shrine and solve the "A Weighty Decision" puzzle.
How to Reach the Shrine
Go east from Lakeside Stable (near Shai Utoh Shrine) and you will reach Lurelin Village. This shrine overlooks the village on a nearby hill northwest of the village.
How to Solve the Shrine
Stand on the side of the scale with the Magnetic Block. Then use Magnesis to put the block on the higher side of the scale.
In the next area, go down the stairs and kill the Guardian Scout, then use Magnesis to lift the treasure chest above the bars. Open it to get a Knight's Broadsword. Then use Magnesis to put the treasure chest on the switch on the other side of the bars beside the gate, then go through the gate.
Use Magnesis to take the treasure chest with you. Put the chest on the left side of the front scale to lower it down. Step on the left side, and then put the treasure chest on the other side to raise yourself up. You can jump and glide to the unopened treasure chest from there. It contains an opal.
Then stand on the scale closest to the wall and use Magnesis to put the treasure chest on the other side. Then stand on the side with the treasure chest, and use Magnesis to put the chest on the other side. Then go to the new area to talk to Yah Rin and get the Spirit Orb.