In a traditional Thai wedding ceremony, the blessed white thread tied around the couple’s wrists is called sai sin.
Sai sin is a sacred cotton thread used in Thai Buddhist ceremonies. During a wedding, monks or elders may bless the couple, and family members can tie pieces of the thread around their wrists while offering good wishes. The practice connects the couple with spiritual protection and the goodwill of the community.
The thread is commonly white, reflecting purity and blessing, though customs vary between regions and families. The wedding may include other rites, such as pouring lustral water over the couple’s hands and placing ceremonial head loops on them.
Sai sin should not be confused with chut thai, the name for traditional Thai clothing, or pha khao ma, a traditional checked cloth. Bai sri is a separate ceremonial arrangement used in some Thai and Lao rites.