What is the test for determining the meaning of a clause in a marriage contract?

In Lucas-Tooth v. Lucas-Tooth, [1921] 1 A.C. 594, Lord Brikenhead, L.C., said at page 601: "Indeed, in approaching a problem of this kind it is important never to lose sight of the true principle of construction in such cases - that it is the duty of the court to discover the meaning of the words used by the Testator, and, from them and from such surrounding circumstances as it is permissible in the particular case to take into account to axcertain his intention. for this purpose, it is important to have regard not only to the whole of the clause which is in question, but to the will as a whole which forms the context to the clause. "Unless this is done, there is grave danger that the canons of construction will be applied without due regard to the Testator's intention, tending thereby to ascertain his wishes by rules which, in the particular case, may produce consequences contrary to that intention."