We have your letter...asking about a Tablet of 'Abdu'l-Bahá on the subject of embracing. We have seen no such Tablet, but we have seen reference to a pilgrim's note and the comment of the beloved Guardian on it.
The pilgrim's note reports the Master as saying: 'Women and men must not embrace each other when not married, or not about to be married. They must not kiss each other... If they wish to greet each other, or comfort each other, they may take each other by the hand.' In a letter to an individual written on behalf of Shoghi Effendi it is said: 'The Master's words to... which you quoted, can certainly be taken as the true spirit of the teachings on the subject of sex. We must strive to achieve this exalted standard.' (October 19, 1947)
(The Universal House of Justice, from a letter dated February 10, 1974 to the National Spiritual Assembly of the United States,; Bahá'í National Review, June, 1979; partially cited in compilation: Lights of Guidance)